Artificial ponds placed in gardens require the use of a filtering device for keeping the water contained therein sufficiently clean.
For this purpose, it is known to the art the use of filtering devices that intake water from the pond, filter it by a filtering element placed therein, and deliver it back inside the pond. Nevertheless, it is evident that the filtering element will be quickly obstructed by impurities and dirt in the pond. Accordingly, such filtering devices have systems for providing a periodical cleaning of the filtering element, so as to remove the impurities and the dirt thereby collected.
Such systems should require only a minimal intervention from the user and, in particular, they should not require any maintenance of the filtering device. For this purpose, it is used a system for cleaning the filtering element that inverts the flow of the water within the device in order to remove impurities and then eliminate the water used for rinsing. This operation is achieved by using selective ducts allowing to modify the flow of the liquid in the device by means of a suitable leverage, and thus taking water from the pond and causing it to flow through the filtering element, without delivering it back in the pond.
Nevertheless, this system does not prove to be enough effective since a simple rinse of the filter does not suffice to a complete removal of the impurities present therein.
In order to obtain an improved cleaning of the filtering element, European Patent EP 1 420 869 to Oase GmbH, describes a filtering device wherein the filtering element is held between two surfaces capable of moving the one near the other so as to press it and thus improving the rinse thereof.
The device described in the patent proves to be little practical in use, since the actuating device allowing the surface to approach each other and press the filtering element, should be used in a particularly uncomfortable working position and it requires a remarkable physical force to perform the operation of compression.
In fact, in this device the surfaces are placed one above the other and a handle is used to raise the lower surface, bring it neared to the upper one and thus comprising the filtering element.
Nevertheless, these filtering devices normally lay underground and, as a consequence, the back of the user operating on the handle is un-conveniently stressed, as the handle, in fact, will need to be pulled upward to press the filtering element.
It should be also understood that this operation could be made by elder people or repeated for several times in big-sized gardens, wherein several ponds filtering devices are present.
Hence, the technical problem underlying the present invention is to provide a filtering device for ponds allowing to overcome the drawbacks mentioned above with reference to the known art.